Audio speakers are extensively utilized in automobiles to generate acoustic signals from the automotive radio. Such audio speakers are frequently placed in the rear of the automobile, most typically below the shelf immediately under the rear window and behind the rear seat. Such audio speakers typically have two leads providing a signal to the speaker voice coil in order to generate the audio acoustic signal. In certain instances, one of the leads would be ground, i.e., the speaker would be grounded either by contact with the vehicle body or by a ground lead extending from the speaker to the vehicle body. The other lead would extend from the speaker through the car, typically under the floor mats, to the radio so that the radio would send the audio signal over the reference lead and through the ground lead to the speaker. In other instances, two leads extend from the speaker to the radio, neither of which is ground but there remains a difference in potential between the leads when an audio signal is being sent to the speaker from the radio.
It is often desired to improve the quality of the speakers in an automobile. This is typically accomplished by replacing the speakers in the automobile with speakers which are amplified by having an amplifier supported by or connected directly to the speaker. The problem with such amplified speakers is that the amplifier at the speaker must be powered and, therefore, an additional power lead must be disposed within the automobile to extend from the speaker amplifier to the radio so that the amplifier on the speaker is powered only when the radio is turned on. In other words, an amplified speaker may not simply be substituted for the speaker in the automobile with the existing leads connected to the speaker because the amplified speaker must be powered and therefore a power line must be extended between the amplified speaker and the radio, which is not an easy task, if the wire is to be hidden.